The Magick_png_malloc function in coders/png.c in GraphicsMagick 6.7.8-6 does not use the proper variable type for the allocation size, which might allow remote attackers to cause a denial of service (crash) via a crafted PNG file that triggers incorrect memory allocation.
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.